I have to say this, because honestly, it surprised me when I tried it out. I've bought lots of cheap Chinese and Mexican steel splitting wedges. Once a piece of flying steel cut me right over my eye. Scared me a lot!!! I carried the fourth one back to my farm and tractor supply store to complain about the way they broke up, mushroomed out and spit a piece of sharp metal at my legs or forehead.This old guy that works there part time stocking shelves came over and asked to look at the offending wedge and just started shaking his head from side to side. I asked him what he saw and he told me that he had been a tool designer and machinist before he retired 12 years prior. He told me that the wedge I brought in was a very cheap Chinese made knock off of an old wedge design he had seen for decades, but that it was just not forged correctly and was made from far inferior steel. Then he took me to a section of the store where they had all American made farming and professional tools. The wedges he had there were between twice and four times the cost of the wedges I had bought before, but I have yet to round off an end or shatter either of the two I bought that day. They are just far superior. I still have the old cheap ones too, and I use them like people typically use the wooden gluts. ...but if I'm starting the lines to split out a stave, I always reach for one of the good steel wedges.
I've also made gluts out of Osage and then I shape the heads on them to fit tightly into a two inch diameter copper pipe cap. Mind I don't drive hard on these. I just use the maul to set the wedges and walk them down the stave to split it out. Make sure you cut you gluts WITH the grain of the wood, and I always put the stump end of the wedge toward the head where you hammer against it. I'm not sure that makes a big difference, but it made sense to me, so I did it that way.
OneBow